This invention relates to mechanism for supporting a portable fire extinguisher in the standby position. The principal aim of the invention is to provide in the support mechanism an audible alarm unit responsive to movement of the extinguisher from the mechanism. When the extinguisher is lifted from the support mechanism an audible warning noise (e.g. siren, whistle, bell ringing) is produced. The warning noise alerts other persons in the area that the extinguisher is being used to put out a fire or that the extinguisher is being stolen. In either event, persons in the area are informed of a situation necessitating some action on their part, e.g. evacuate the area, assist the person putting out the fire, apprehend the thief, etc.